2026 Laws of MotionFriction - maximum acceleration without relative sliding Medium Question 2 of 72 in Laws of Motion

A box of mass 15 kg is kept on the floor of a stationary trolley. The coefficient of static friction between the box and the trolley is 0.12. Keeping the box in stationary state over the trolley, the maximum acceleration with which the trolley can be moved horizontally in $m\,s^{-2}$ is: ($g = 10\ m/s^2$)

A 1.5
B 1.8
C 2.1
D 1.2

The answer is D.

Solution

In the trolley frame, a pseudo force $ma$ acts on the box opposite to the acceleration; static friction must balance it. For the maximum acceleration: $ma_{max} = f_{lim} = \mu mg$ $a_{max} = \mu g = 0.12 \times 10 = 1.2\ m/s^2$

Laws of Motion in past papers

72 questions from this chapter have appeared across 27 exam years.